Doseong Co., Ltd. was developed to handle the land, save water, conserve the environment and ultimately conserve people. There is a founding philosophy of Dooseong that contributes to the country, makes the country and mankind healthy by using the very special resource (Ge-lite) that God has prepared for our people in the 21st century.
Pozzolans are silicate-based materials that react with (take in) the calcium hydroxide generated by hydrating cement to form extra cementitious products.
Using Pozzolans In Concrete:
Why is consuming calcium hydroxide a good thing? Calcium hydroxide (lime) represents approximately 25% of the hydrated Portland cement, and lime does not contribute to the concrete's strength or resilience. Pozzolans combine with the lime to produce extra calcium silicate hydrate, the product responsible for holding concrete together. By taking in the excess lime:
The strength of the concrete is increased
Its density is increased
Efflorescence is decreased
The propensity for alkali-silica reaction (reaction with glass) is decreased, and even practically gotten rid of
Generally pozzolans are utilized as cement replacements instead of cement additions. Including pozzolans to an existing concrete mix without removing an equivalent amount of cement increases the paste content and reduces the water/cement ratio. Simply put, including more pozzolans to a mix alters the mix proportions. Changing some of the cement with pozzolans maintains the mix percentages. Pozzolans change cement pound for pound.
Relying on the particle size, chemical structure and dose, different pozzolans will impact the concrete strength in a different way and at different times during curing. Numerous pozzolans are waste products from industrial processes. Fly ash comes from coal-fired power plants, and silica fume and slag originates from some steel refineries. As such the color, quality, gradation and residential or commercial properties can differ and are not managed.
VCAS and metakaolin are actively produced pozzolans. Quality, color and other attributes can be controlled, so item consistency is greater. There might also be various grades available. A lot of pozzolans are utilized individually, but blends of two or more different pozzolans can be utilized to take advantage of the characteristics each pozzolan provides. Case in points are fly ash and silica fume blends, where the fly ash increases workability and particle packing and the silica fume helps with early strength and overall strength development.